Compressive residual stresses are often introduced into components which are subject to high mechanical loads, to enable the components to withstand increased stresses. This is in some cases carried out in the case of fir-tree-like roots of blades or vanes of turbines (steam turbines, gas turbines).
Compressive residual stresses can be introduced by roller-burnishing. Another way of generating compressive residual stresses is shot-peening. U.S. Pat. No. 5,911,780 shows a method of this type for generating compressive residual stresses.
U.S. Pat. No. 5,492,447 discloses a process for generating compressive residual stresses in rotor components by means of a laser.
A similar process is disclosed in EP 731 184 B1.
WO 01/15866 A1 shows a process for the surface treatment of a component in which at least one peening parameter in an abrasive peening process is adapted to the contour line of the component. DE 197 42 137 A1 shows a rolling apparatus for generating compressive residual stresses.
U.S. Pat. No. 4,428,213 discloses a component in which a first region and then the entire component are shot-peened with a lower intensity.
EP 0 230 165 A1 and EP 1 125 695 A2 disclose a robot which guides a tool with respect to a component that is to be processed.
U.S. Pat. No. 4,937,421 discloses a laser irradiation method and an associated apparatus, in which the laser beam from a laser is split into two beams in order in this way to generate a larger irradiation surface area on the component to be processed, thereby achieving a faster processing time. These two laser beams are guided jointly and have the same parameters in terms of angle of incidence and intensity, and are guided jointly in one holder.
Components according to the prior art do not have sufficient strength for unusual operating states with regard to the desired demands imposed on the locally different operating stresses.